Let me know when you do. I want one also.
Ditto Jeep’s Phoenix. The Extra Fine Precise V5 Rolling Ball pen is my first choice. The Bic Ultra Round Stic Grip pen is the next favorite, but I much prefer that in a Medium tip.
My writing is huge, so any fine-tip pen other than the V5 looks anemic.
On preview, looks like I join the illustrious company of Jeep’s Phoenix, yellowval and tremorviolet. I had no idea my seemingly obscure penchant for the V5 was so widespread. 
Ohh, I’d like that too. As it is, I prefer extra-fine but often find myself using medium points because that’s what happens to be handy at the time.
I had no idea there were so many of us either. Nobody else I know IRL uses them.
Typewriter / computer printer. My writing is extremely legible but utterly horrible. Well, it used to be. I haven’t written anything significant longhand for many years.
Is super-fat tip a choice? With pencils, I buy the .9mm (or 1.2mm, when I can find them) mechanical pencils marketed towards children. I don’t do much writing in pen, but I have a disposable fountain pen that gives a nice, thick flow of ink. Off the top of my head, I forget the brand. If I’m jotting down a note on one of my second grader’s papers such as “Watch out for capitalization errors!”, I’ll use the magic marker I’m grading with.
Medium for ballpoint, I think I’d crush a fine tip. My favourite pen, though, is a fine-tipped fountain pen, for some reason I write with a lighter hand when I use it.
The Pilot V5 is sexy as hell, feels so good writing on paper. That said, as standard I prefer .5 mm as standard unless I’m writing kanji, when .3 comes in handy. .7 makes me feel like I’m a sloppy drunk and oozing ink all over because I can’t keep it in my pants… or something.
I’m another fan of the ultra-fine tip. I like the Pilot, but my current pen of choice is the Uni-Ball Signo Micro, which has an 0.5mm tip (same as the Extra-Fine on the Pilot Precise), but with a rubber grip and a click-retractable pen tip instead of having a cap (which I always lose).
I like a different pen depending on what I’m writing. For really dreamy, creative, right brain stuff, I like an ultra-fine pen, but for violent stuff, threats, and checks I want a black medium-point. Uni-Ball pens are the instrument of choice for on-the-go writing, and a mechanical pencil is necessary for writing notes to my husband (which often require diagrams).
I bet your love letters are a hoot.
As fine as I can get it.
My current favorite “commodity” pen is the Pilot G2.
Medium for me; specifically, a Bic medium ballpoint, always black. I’ve got a heavy hand and can go through the paper with fine or extra-fine.
Medium, because I cannot tolerate a scratchy pen.
I use colored pencils for those.
Fine, all the way. Medium looks like crayon to me.
Ditto. The feeling in my hand when I write with fine or extra-fine makes my hair stand on end. Even with a medium, I prefer to put my paper on a stack while I write to reduce the harshness of the feedback from the tip. On top of that, my writing is not middle-school-girl-giant, but it’s not tiny either. It just looks wrong with a fine point.
When I leave notes at work, I usually do it in fine-point Sharpie (even BIGGER than medium pen), which is my favorite writing utensil. They make an extra-fine, but that’s just wrong.